You can change the style the forum displays by selecting your preferred style at the bottom left of the site.
We have made an enhancement so that old threads should now link from search results to the correct thread. This is not yet in place for single post links
have a really annoying misfire under acceleration. from 3k onwards its missing like a feker ! Replaced all boost pipes,plugs,got new boots on the way(as precaution) and this morning checked the coilpacks.
Nothing............
so after doing some searching am narrowing it down to the POS. Anybody got a price or have spares? i am aware v6 ones can be used.
In my experience, if one channel of a POS goes, it's gone end of. You'll be on one less cylinder all the time.
A coilpack could be working at idle, but as soon as it's asked for more under a high load, high boost situation, it can missfire. Again, as I've been in this boat twice in varying situations, it's not been a coilpack, but the wiring to and from it that has been the suspect, and in the end, the villian. Unfortunately the loom to and from the coilpack isn't a separate part, which is a bit of a PITA.
Jas..
2001 Avus Silver B5 RS4.
2004 A4 Avant 1.8T quattro Sport-LE.
1995 S2 Coupe - sold (sniff)
ok,interesting ta. it idles perfectly.the weather just seems be ***** all the time at the moment so cant get out to stripit down. would it be worth swapping the plugs to the pos? or would this just transfer the misfire to another cylinder?
You see, this is the PITA bit. Because the car idles ok, at the minute you have no idea which cylinder/coilpack is the one that is missfiring. Just unhooking the two multiplugs that come direct from the coilpacks and switching them over would cause the car not to run at all as you'd change the firing order.
Switching over POS's still isn't going to identify which is the bad coilpack as the car idles ok.
Checking the wiring isn't easy, it's not as if both wires that emerge from each coilpack go down a nice clearly defined route to the connectors onto the POS's, they don't, they both bloody split up and go different routes
I tried on mine, really did give it a go to try and find where the wiring was bad (apart from it all being cracked at the coilpack itself) but in the end I got fed up and bought five new coilpacks. Not the most economical way I know, but it was the easiest without resorting the either replacing every damn wire or settling for a team bodge 1.8T retrofit.
Have you still got these digitec chips in? when I had some fitted it would stutter and misfire like a bas""rd at times.
Jas..
2001 Avus Silver B5 RS4.
2004 A4 Avant 1.8T quattro Sport-LE.
1995 S2 Coupe - sold (sniff)
yeah still got the chips. im in contact with the previous owner (we swapped cars) and he said it would only misfire occasionly but now im driving it loads and its getting worse.
would vagcom be able to diagnose it? or the l.e.d test? its doing mw swede in !!
The only codes that would come up relating to a missfire would be if they were injector related, for some daft reason the coilpacks and POS's aren't monitered by the ECU.
But, pulling codes for me is always a first job.
2001 Avus Silver B5 RS4.
2004 A4 Avant 1.8T quattro Sport-LE.
1995 S2 Coupe - sold (sniff)
There is a logical way to find out what is the cause of the missing or hesitation. In this case, because the engine idles smoothly, its probably a coil. The procedure to confirm whether its a coil or POS channel that I wrote for the UrS forum on AudiWorld is here:
I had the same problem, i would'nt say i had a misfire 90% of the time but certainly more like a hesitation under boost, some days (the other 10%) it was really bad and was using massive amounts of fuel it just was'nt running right and felt like it was holding back everytime i gave it beans.
I changed the plugs, checked my boots (4 were new 4000 miles ago) but still did this and had no codes come up on the ECU.
I decided to clean the MAF in IPA, oh boy what a difference it made, hesitation is gone and its a flyer now much much better and really strong in the mid-range.
For the sake of £11 (for a litre from maplins) i would definetly try this!
'95 ABY Avant - Sold
'98 B5 S4 -MRC400+ = 464ps 741nm
well glad you suggested that as my bird is shopping at the minute so ive sent her to get some.
Although i think i may have found the problem.....managed to dodge the showers and strip it all down and found the 5th coil had a clean snap on it where the boot fits on. knew i needed another so have sourced one, so as a bodge i taped it up.
guess what............? ran perfect on tickover!!
so hopefully that should be sorted,along with maf cleaning and a pos sensor......he says
We process personal data about users of our site, through the use of cookies and other technologies, to deliver our services, personalize advertising, and to analyze site activity. We may share certain information about our users with our advertising and analytics partners. For additional details, refer to our Privacy Policy.
By clicking "I AGREE" below, you agree to our Privacy Policy and our personal data processing and cookie practices as described therein. You also acknowledge that this forum may be hosted outside your country and you consent to the collection, storage, and processing of your data in the country where this forum is hosted.
Comment